For origination 408s Twilio advises confirming the trunk's Origination SIP URI and checking that the firewall and PBX allow Twilio's IP addresses and ports.
Checked 2026-10-02
- Vendor
- Twilio
- Product
- Twilio Elastic SIP Trunking
- Subsystem
- origination
- Deployment
- multi-tenant
- Region
- not restricted
- Release range
- current as of 2026-10-02
- Checked
- 2026-10-02
Sources
- Troubleshooting your Trunk — Twilio · tier 2 current vendor documentation · Origination section, solution list under the 408/504 problem
Cite this note
APA
WarmTransfer. (2026, October 2). Troubleshooting SIP 408 Request Timeout and calls that get no response: source note sip-408-timeout-troubleshooting-twilio-408-allow-ips. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-408-timeout-troubleshooting-twilio-408-allow-ips
BibTeX
@misc{warmtransfer-claim-sip-408-timeout-troubleshooting-twilio-408-allow-ips,
title = {Troubleshooting SIP 408 Request Timeout and calls that get no response: source note sip-408-timeout-troubleshooting-twilio-408-allow-ips},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-408-timeout-troubleshooting-twilio-408-allow-ips},
note = {Source note sip-408-timeout-troubleshooting-twilio-408-allow-ips, checked 2026-10-02}
}